Comparing signal amplification of thiocyanated Gold nanoparticles in the presence of different ions

Detecting is the most important section in all kinds of sensors. In this regard, the amplification of surface plasmon resonance intensity of gold colloids nanoparticles (GNPs) was studied in the presence of several ions. GNPs were synthesized and then capped by thiocyanate and characterized via DLS and TEM image. In the next step the effect of different concentrations of ions such as iron, copper and iodide, for the suitable amplification of surface plasmon resonance intensity of GNPs, were investigated. This amplification studies were followed by UV-Vis and fluorescence spectroscopy. The results also could be observed by the naked eye. It was showed that iron ions were the best amplifier for the surface plasmon resonance of GNPs. The results lead to an extraordinary change signals of GNP peaks and developed a simple and new probe for tracking immunosensor system. This process seems to promote the sensitivity and selectivity of colorimetric biosensors rather than the previous method.